Merge "Brightness key control: apply linear increment instead of gamma" into udc-dev am: 7429467d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21480128



Change-Id: Ie501e0239cb574d8e9fdb4d602da0d239a6fb555
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>